The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Transmissions contain several parts that are mated together via splines, or teeth and grooves, which maintain the angular position between the parts. The splines allow the splined transmission parts to slide axially along the splines, but not rotationally, because the teeth and grooves mate to each other to prevent the parts from turning relative to each other.
For example, typically, at least some of a transmission's clutch plates have outer teeth that mate with opposed grooves in a transmission case component, such as a transmission case, central support, clutch housing, or other case component. As such, toothed clutch plates may be slid into the case component along the teeth and grooves of the case component. The mated splined prevent the clutch plates from rotating relative to the case component, but the mated splines typically do not prevent axial movement of the clutch plates along or parallel to the central axis of the case component. An additional component is typically used to prevent axial movement of the clutch plates relative to the transmission case component. At one end, that additional component is typically a snap ring. The apply piston typically constrains movement of the clutch plates at another end. Other components of a transmission may also have a tooth and groove spline interconnecting arrangement.
Typically, clutch assemblies include a backing plate that also has outer splines that mate with inner splines of the transmission case component, and the snap ring prevents the backing plate from sliding past the desired axial location. The backing plate provides clutch pack support to enable proper deflection and uniform friction load distribution. The backing plate typically has a face that contacts a friction plate to provide surface finish, straightness, and taper onto which the friction plate is applied. Automotive transmissions often have multiple clutch assemblies, each with corresponding backing plates and snap rings. While the current arrangement works for its intended purpose, automotive manufacturers strive toward reducing the size and weight of components and the number of components that are needed.